(1) Field of the Invention
The invention relates to a coupling-free unit for the transmission of torque and damping of torsional vibrations for motor vehicles, boats and other forms of transportation having an internal combustion engine for driving auxiliary assemblies, such as, for example, a fan, a compressor of an air conditioning system, an electric generator, water pump, hydraulic pump, or a compressor for the brake system driven by the internal combustion engine.
The invention furthermore relates to a unit for the contactless transmission of torque and damping of torsional vibrations for motor vehicles and other forms of transportation having an internal combustion engine and a transmission disposed between a wheel or propeller drive, for example the propeller shaft.
(2) Description Of Related Art Including Information Disclosed Under 37 C.F.R. 1.97 and 1.98
Irregular operating states occur frequently in internal combustion engines which have to meet the strict EU requirements for low fuel consumption and low quantity and cleanness of exhaust gas emissions. For example irregular operating states occur at low idling speeds. Generally known, vibration-damping transmission of torques by means of V-belts can no longer sufficiently dampen these irregular operating states. Another complicating factor is that the number of auxiliary assemblies which are required has greatly increased and will increase further. When a number of such auxiliary assemblies interact, superpositions of torsional vibrations may occur, augmented by each individual auxiliary assembly. It is becoming less and less sufficient to dampen by one or more parallel V-belts which permits/permit the transmission of torque from the driven belt pulley on the shaft of the drive to a driving belt pulley on the shaft of the auxiliary assembly. On the one hand, the V-belt has to have high strength in order to be able to transmit the torques and ensure a long service life but on the other hand, it is to be elastic to effectively dampen the torsional vibrations. A V-belt is only able to a limited extent satisfy these contradicting requirements.
A catalog from CENTA discloses, under the trademark Centaflex, a component which comprises two housing halves. Mutually corresponding recesses are arranged on opposite surfaces of the housing parts. One or more specially shaped, elastic plastic parts are inserted into these recesses. These elastic plastic parts take on the transmission of torque, and are intended, according to the manufacturer's instructions, also to carry out sufficient damping of the torsional vibrations. Such a design has the drawback that its elastic plastic parts wear out over the course of time because of the high endurance and transmittal torques combined with vibrations. Such plastic parts first of all lose their initial elasticity and finally disintegrate. The wear is furthermore accelerated by a thermal loading of the plastic parts used for damping; the typical temperatures of between up to −40° C. and +120° C. are common in the vicinity of internal combustion engines. In addition a large variety of types of elastic plastic parts are required having different degrees of hardness for the driving and auxiliary assemblies due to the different frequencies and amplitudes that may occur and which have to be transmitted and damped. The exchange of worn plastic parts results in a high and cost-intensive outlay for maintenance.